【摘要】 在颗粒流方法 PFC^3D的基础上发展了颗粒-流体耦合模型。在耦合模型中引入了孔隙度,其可考虑孔隙结构的可变性,并开发了可以考虑孔隙水压力和孔隙结构变化的颗粒-流体耦合计算程序。在此基础上模拟了饱和土的不排水剪切试验,与北京黏质粉土的试验数据及常体积模拟方法进行了对比。结果表明:采用颗粒-流体耦合方法计算得到的结果和常体积法计算结果与北京黏质粉土的试验结果相比均是一致的,验证了耦合算法的可靠性;分析比较了相同计算条件下耦合方法和常体积法计算得到的偏应力及径向应变曲线,研究了不同围压下试样的不排水剪切特性。颗粒-流体耦合计算结果表明:饱和土不排水剪切过程随着围压升高,孔隙水压力和偏应力均升高,而应力比曲线变得平滑,应力比有所降低。更多还原

【Abstract】 A fluid-particle coupled model is developed based on particle flow code 3D. The porosity is introduced to characterize the change of void structure. A fluid-particle coupled code is developed with considering pore pressure and the change of void structure. The proposed method is used to simulate the undrained shear behavior of saturated soil. The calculated results are compared to the experimental results from constant-volume experiments on Beijing clayey silt. The results show that the deviatoric stress by fluid-particle coupled method is consistent with the experimental results, showing the capability of the proposed fluid-particle coupled method. The deviatoric stress curves and radial strain curves by constant-volume and fluid-particle coupled methods are analyzed under the same conditions. Undrained shear behavior of saturated soil under different confining pressures is studied. It is shown that as the confining pressures increase, the pore pressures and deviatoric stress increase, while the stress ratio decreases, and the curve of stress ratio is increasingly smooth.更多还原